text: # Copyright (c) 2001-2007 Twisted Matrix Laboratories.
  # See LICENSE for details.
  
  
  """
  A kqueue()/kevent() based implementation of the Twisted main loop.
  
  To install the event loop (and you should do this before any connections,
  listeners or connectors are added)::
  
      | from twisted.internet import kqreactor
      | kqreactor.install()
  
  This reactor only works on FreeBSD and requires PyKQueue 1.3, which is
  available at:  U{http://people.freebsd.org/~dwhite/PyKQueue/}
  
  Maintainer: Itamar Shtull-Trauring
  
  
  
  You're going to need to patch PyKqueue::
  
      =====================================================
      --- PyKQueue-1.3/kqsyscallmodule.c	Sun Jan 28 21:59:50 2001
      +++ PyKQueue-1.3/kqsyscallmodule.c.new	Tue Jul 30 18:06:08 2002
      @@ -137,7 +137,7 @@
       }
       
       statichere PyTypeObject KQEvent_Type = {
      -  PyObject_HEAD_INIT(NULL)
      +  PyObject_HEAD_INIT(&PyType_Type)
         0,                             // ob_size
         "KQEvent",                     // tp_name
         sizeof(KQEventObject),         // tp_basicsize
      @@ -291,13 +291,14 @@
       
         /* Build timespec for timeout */
         totimespec.tv_sec = timeout / 1000;
      -  totimespec.tv_nsec = (timeout % 1000) * 100000;
      +  totimespec.tv_nsec = (timeout % 1000) * 1000000;
       
         // printf("timespec: sec=%d nsec=%d\\n", totimespec.tv_sec, totimespec.tv_nsec);
       
         /* Make the call */
      -
      +  Py_BEGIN_ALLOW_THREADS
         gotNumEvents = kevent (self->fd, changelist, haveNumEvents, triggered, wantNumEvents, &totimespec);
      +  Py_END_ALLOW_THREADS
       
         /* Don't need the input event list anymore, so get rid of it */
         free (changelist);
      @@ -361,7 +362,7 @@
       statichere PyTypeObject KQueue_Type = {
              /* The ob_type field must be initialized in the module init function
               * to be portable to Windows without using C++. */
      -	PyObject_HEAD_INIT(NULL)
      +	PyObject_HEAD_INIT(&PyType_Type)
              0,			/*ob_size*/
              "KQueue",			/*tp_name*/
              sizeof(KQueueObject),	/*tp_basicsize*/
  
  """
  
  import errno, sys
  
  from zope.interface import implements
  
  from kqsyscall import EVFILT_READ, EVFILT_WRITE, EV_DELETE, EV_ADD
  from kqsyscall import kqueue, kevent
  
  from twisted.internet.interfaces import IReactorFDSet
  
  from twisted.python import log, failure
  from twisted.internet import main, posixbase
  
  
  class KQueueReactor(posixbase.PosixReactorBase):
      """
      A reactor that uses kqueue(2)/kevent(2).
  
      @ivar _kq: A L{kqueue} which will be used to check for I/O readiness.
  
      @ivar _selectables: A dictionary mapping integer file descriptors to
          instances of L{FileDescriptor} which have been registered with the
          reactor.  All L{FileDescriptors} which are currently receiving read or
          write readiness notifications will be present as values in this
          dictionary.
  
      @ivar _reads: A dictionary mapping integer file descriptors to arbitrary
          values (this is essentially a set).  Keys in this dictionary will be
          registered with C{_kq} for read readiness notifications which will be
          dispatched to the corresponding L{FileDescriptor} instances in
          C{_selectables}.
  
      @ivar _writes: A dictionary mapping integer file descriptors to arbitrary
          values (this is essentially a set).  Keys in this dictionary will be
          registered with C{_kq} for write readiness notifications which will be
          dispatched to the corresponding L{FileDescriptor} instances in
          C{_selectables}.
      """
      implements(IReactorFDSet)
  
      def __init__(self):
          """
          Initialize kqueue object, file descriptor tracking dictionaries, and the
          base class.
          """
          self._kq = kqueue()
          self._reads = {}
          self._writes = {}
          self._selectables = {}
          posixbase.PosixReactorBase.__init__(self)
  
  
      def _updateRegistration(self, *args):
          self._kq.kevent([kevent(*args)], 0, 0)
  
      def addReader(self, reader):
          """Add a FileDescriptor for notification of data available to read.
          """
          fd = reader.fileno()
          if fd not in self._reads:
              self._selectables[fd] = reader
              self._reads[fd] = 1
              self._updateRegistration(fd, EVFILT_READ, EV_ADD)
  
      def addWriter(self, writer):
          """Add a FileDescriptor for notification of data available to write.
          """
          fd = writer.fileno()
          if fd not in self._writes:
              self._selectables[fd] = writer
              self._writes[fd] = 1
              self._updateRegistration(fd, EVFILT_WRITE, EV_ADD)
  
      def removeReader(self, reader):
          """Remove a Selectable for notification of data available to read.
          """
          fd = reader.fileno()
          if fd in self._reads:
              del self._reads[fd]
              if fd not in self._writes:
                  del self._selectables[fd]
              self._updateRegistration(fd, EVFILT_READ, EV_DELETE)
  
      def removeWriter(self, writer):
          """Remove a Selectable for notification of data available to write.
          """
          fd = writer.fileno()
          if fd in self._writes:
              del self._writes[fd]
              if fd not in self._reads:
                  del self._selectables[fd]
              self._updateRegistration(fd, EVFILT_WRITE, EV_DELETE)
  
      def removeAll(self):
          """Remove all selectables, and return a list of them."""
          if self.waker is not None:
              self.removeReader(self.waker)
          result = self._selectables.values()
          for fd in self._reads.keys():
              self._updateRegistration(fd, EVFILT_READ, EV_DELETE)
          for fd in self._writes.keys():
              self._updateRegistration(fd, EVFILT_WRITE, EV_DELETE)
          self._reads.clear()
          self._writes.clear()
          self._selectables.clear()
          if self.waker is not None:
              self.addReader(self.waker)
          return result
  
  
      def getReaders(self):
          return [self._selectables[fd] for fd in self._reads]
  
  
      def getWriters(self):
          return [self._selectables[fd] for fd in self._writes]
  
  
      def doKEvent(self, timeout):
          """Poll the kqueue for new events."""
          if timeout is None:
              timeout = 1000
          else:
              timeout = int(timeout * 1000) # convert seconds to milliseconds
  
          try:
              l = self._kq.kevent([], len(self._selectables), timeout)
          except OSError, e:
              if e[0] == errno.EINTR:
                  return
              else:
                  raise
          _drdw = self._doWriteOrRead
          for event in l:
              why = None
              fd, filter = event.ident, event.filter
              try:
                  selectable = self._selectables[fd]
              except KeyError:
                  # Handles the infrequent case where one selectable's
                  # handler disconnects another.
                  continue
              log.callWithLogger(selectable, _drdw, selectable, fd, filter)
  
      def _doWriteOrRead(self, selectable, fd, filter):
          try:
              if filter == EVFILT_READ:
                  why = selectable.doRead()
              if filter == EVFILT_WRITE:
                  why = selectable.doWrite()
              if not selectable.fileno() == fd:
                  why = main.CONNECTION_LOST
          except:
              why = sys.exc_info()[1]
              log.deferr()
  
          if why:
              self.removeReader(selectable)
              self.removeWriter(selectable)
              selectable.connectionLost(failure.Failure(why))
  
      doIteration = doKEvent
  
  
  def install():
      k = KQueueReactor()
      main.installReactor(k)
  
  
  __all__ = ["KQueueReactor", "install"]
  